When Warren Gatland's glittering 12-year tenure as Wales coach ended last year, he said it would break his heart if the team "went back into the doldrums" following his departure.

Wales are still far from sinking to the depths where they floundered before Gatland's arrival - but there have been some signs of regression under his successor, Wayne Pivac.

Wales have lost four of their five Tests under the former Scarlets coach, whose vision of a more adventurous brand of rugby has yet to be realised, while a defence renowned for its solidity under Gatland is now concerningly porous.

This is all still of great professional interest to Gatland, who as British and Irish Lions head coach, is monitoring his former players ahead of next summer's tour of South Africa.

But this is personal too, for a man who helped build this Wales side.

"You've got a new coaching team who are coming to grips with what they're trying to achieve and that's challenging," says Gatland.

"You're under so much scrutiny for not so much performances but results, and you don't get a lot of time.

"When you're with a club side, you get a chance to fail. As you're trying to work on things, it doesn't count your whole season out.

"International rugby is a hell of a lot more pressure."

Pivac has discovered as much in his short time as Wales boss.

Last Saturday's defeat against France in Paris - a warm-up match for this autumn's delayed conclusion of the Six Nations - was a chastening experience.

Wales play Scotland this Saturday in their rescheduled final Six Nations fixture. With only one win from their first four games, the reigning champions have spent this week referring to the Parc y Scarlets encounter as a "must-win" game.

'Step-up for Pivac is massive'

Since beginning Pivac's reign with a 42-0 victory over Italy, Wales have conceded 15 tries in four games.

By contrast, they shipped only seven tries in five matches under Gatland and former defence coach Shaun Edwards on their way to winning the 2019 Grand Slam.

"I think the players and coaches have kind of realised the step-up from club or regional rugby to international rugby is massive," Gatland says.

"For example, on the weekend, France kicked the ball 36 times and Wales kicked it 30 times. That's an average number for international games and not just for Wales and France but for all teams, the All Blacks as well.

"And when you play domestic competitions that number is a lot lower - there's more time and space.

"So I think they're just trying to find a balance. They've talked about playing a new way and that's absolutely fantastic and I hope they're able to achieve that.

"They've just got to make sure they're pragmatic about the way they approach things.

"Sometimes for us, it was trying to do the simple things right.

"We worked hard on our defence, we worked hard on our kicking and aerial game, we did contact every day because those are the important factors about trying to get the best out of your players. That's what international rugby is about."

Gatland does not explicitly criticise Pivac or his assistants but the aspects of Wales' game which he highlights are revealing.

Defence, physical collisions, kicking and aerial skills are all areas where Wales excelled under Gatland - and also where they have been found wanting under Pivac.

Those weaknesses were laid bare against France last weekend, and Pivac spoke afterwards about the need to improve before facing Scotland.

'Is Scotland game really must-win?'

With European Champions Cup winner Stuart Hogg and runner-up Finn Russell in their ranks, the Scots are confident of a first away win against Wales since 2002.

Pivac and his coaching staff seem to be embracing the pressure by referring to this fixture as "must-win" - but Gatland questions that approach.

"They're already talking about this game as a must-win game," says the 57-year-old, who is back in New Zealand coaching the Chiefs.

"Is it really a must-win game? The Six Nations is important but they're going to finish fourth or fifth so does it really matter?

"Use this autumn period to think about building towards the [next] Six Nations, developing players over the next two years and the World Cup is another factor.

"They've got the luxury and I don't know whether it's luck but the fact the World Cup draw has put them in a position when they ended up being top seeds, which takes a massive amount of pressure off them in their preparations for the next couple of years.

"Maybe the approach is you take a bit more of a realistic view, a more long-term view and what you're trying to develop, looking at combinations and gameplans, and forgetting about external pressures.

"That might be the way forward, and I know that from personal experience.

"That's what they need to think about - forget about external pressure and make sure they're focused on what they want to achieve, first in the short term and then the long term.

"So forget about all the stuff people are saying about them and the pressure that's coming from the outside."